Floating punch.



P. G. PATER. FLOATING PUNCH. APPUCATION FILED MAY 20. 1918. 1,298,088. Patented Mar. 25, 1919.

2 SHEETSSHEET 1.

Inventor Witness: M/JZWZI W M w. 3%

I Attorney P. G PATER.

FLUATING PUNCH.

APPLECATIONV HLED MAY 20A 1918.

Patented Mar. 25, 1919 H Fm w H wv m m m P M m .1 F W 7% fizz/4,66% B) W W 8% Attorney UNITED STATES i PATENT onnicn.

PAUL G. PATER, OF HAMILTON, OHIO, ASSIGNOR 'TO THE LONG 85 ALLSTATTER COMPANY, OF HAMILTON, OHIO.

FLOATING PUNCH.

To all whom it may concern:

Be it known that I, PAUL G. Pawns, a citizen of the United States, residing at Hamilton, Butler county, Ohio, have invented certain new and useful Improvements in Floating Punches, of which the following is a specification. p k N This invention relates to improvements in that class of metal punches, often referred to as floating punches, designed to facilitate the accurate positioning of the plate to be punched rior to the punching stroke.

A punch, having punched a hole through a plate must, of course, in withdrawing therefrom rise a distance equal to the thickness of the plate inorder to permit the shifting of the plate fora new punching. A stripping device must be present to hold the plate down while the punch is rising, and this stripper will not be nicely down upon the plate but will be some little distance above it, which distance will be called the stripper clearance, Again, as the punch withdraws fromthe plate, the margin of the hole may pout upwardly somewhat, the consequence being that, in order to properly clear the plate, the punch must rise at least the thickness of the plate plus the stripper clearance plus the possible pouting. Punch-{construction recognizes these conditions and pro vides a further excess of stroke, so that the punch, in its uppermost positiomvery freely clears the plate and, quite likely, has such further excess of stroke'as to permit of the punching of thicker plates. v

In positioning the plate, prior; tothe punching, and assuming that the punching is not done through a templet, two plans are open to employmentin the-marking of the plate-to indicate where the punching is to be done. the intended hole by means of prick-punching or by imprintingthe area of the intended hole with pigment, the otherplan being to prick-punch the center of the intended hole, and provide the punch with; ateat' to engage this prickspunch mark, [The first plan depends on eyesight, and the second plan depends on the feel of. things asthe teat enters the prick-punch mark during the shifting of the late. The utilization of either plan, and particularly the second one, necessitates that, in adjusting the plate, the punch be close down to it, and this is in- One plan is to mark theoutline of Specification of Letters Patent. Patented Mar. 25, 1919.- Application filed ma 20, 1918. Serial No. 235,469.

consistent with the high position of the punch following the stripping. This, inconsistency has recently brought about the development of floating punches in which the punch is vertically free in the ram which operates it, the rain being connected with the punch by means of a let-go device, automatic or manual, which releases the elevated punch and permits it to descend and float upon the plate regardless of the thickness of the plate. I My present invention directs itself to a construction permitting the let-go device to be dispensed with and at the same time facilitating dealing with plates of varying thicknesses. I

The invention will be readily understood from the following. description .taken'in connection with the accompanying drawings in which Figure 1 is a side elevation of an ordinary punching machine fitted with my improvements:

Fig. 2 a face elevation of. the movable clutch member of the automatic clutch:

Fig. 3 a side elevationof the same:

V Fig. 4: a vertical, section of the same in the plane of line of Fig. 2: i i

Fig. 5 a front view of the die:

Fig. 6 a front elevation of the ram and, its punching accessories:

Fig. 7 a vert'cal section of the same in the plane of line a of Figs. 6 and 8: and

Fig. 8 a horizontal section of the ram in the plane of line 0 of Figs. 6 and 7 A diversity of scales is employed in the drawings.

-i In the drawings .1, indicates frame portions of. the machine:

2, the cam shaft 1 3, the ram or slide which carries the punch:

4, the diez.

, 5 the sliding member of the automatic 7 clutch? to p y 6, the switch carried thereby: r

7, the release-pin of the automatic clutch mechanism: 8, the plate to be punched:

9, the punch: and

10, the stripper. 1 p I All of the parts thus far referred: to, with the exception of features hereinafter more The usual operation of the parts thus. far

referred to may lows The ram and punch are up; the camshaft be briefly described as folis; unclutched from the driving power and held so by the release-pin; the plate to be punched is positioned; the release-pin is lifted; by momentary action on the treadle;

the spring causes'the clutch to engage; the ram and punch descend and make their punching stroke ;they ascend and the strip ping is done; theswit'ch engages the re lease-pin. and disengages the clutch; the punch comes to, rest in upper position; the platemay be shifted for a new punching, and so on and on. The punch, being in its uppermost position, asuhas been assumed, would be so 'far above the plate as to be of little use as an aid in. positioning the plate for thenext punching,'as has been heretoforejmore fully explained. The improvemerits will now be explained Continuing with the drawings ll, indi cates a punch-stock connecting the punch withthe ram;

12, a bushing adj ustably screwed into the base of the ram, the punch-stock being free to slide in the bore of this,bushing,-the upper end of this bushing forming an upwardly presenting abutment: carried by the ram:

l3,a head on the upper end of the punchstock and adapted toengage the abutment justing the top of the die:

formedby the upper end of the bushing:

14:; an abutment carried by the ram above the head of the punch-stock and adapted for. downward engagement with it to impart'the punching force:v

15, a block secured 'i n the front of the ram at its base, the threaded bore in-which the bushing is screwed being formed half in the ram and half in this block:

16, a radial set-screw through the wall of the bushing with its point loosely engaging a keyway in the punch-stock; y

17 ,a shim under'the die or die-block, this shim typifying means for vertically ad- 18, a groove formedin the peripheryof the movable member- 5 of the automatic clutch:

c 19, a switch-ring surrounding andirotary upon the grooved portion ofthelhtch-m'emher, this switch-ring bearing the switch 6':

20, pins screwed through the switch-ring and having their inner ends engaging the groove in the clutch member, so'ias-toprevent the sidewise displacement of theswitchring without interfering with its rotation on the clutch member: and t 21, set screws passing th'rough;-the switchring and bitingthe bottom of the groove in at rest, a condition brought about by the 7 of events of the improveddevice would be as follows:

Theram is at rest somewhat below its uppermost limit ofstroke; the punch is floatingon the plate; the head of the punch is free fromengagement by the bushing underneath it or by the abutment 14 over it; the plate may be shifted as desired :until it is properlypositioned"for a new punching;

the treadle is momentarily actuated; the

clutch engages; the ram descends and its abutment engages the top of the punchstock and forces the punch through the plate; the ram starts on its rising motion; it picks up the punch by the engagement of the bushing with-the headolf' the punchstock; the punchis raisedsuliiciently to take i care ofthe stripper clearance" and of'any possible-pouting; the ram having reached the topof its stroke, descends somewhat; the release-pin (zauses-*the disengagement of the clutch; theram 'comesto rest; the punch has descended-with the ram until it reaches the plate; the punch now floats on the plate; the conditions are as indicated in Figs. 6 and 7, with the head of tliepunchstock freefrom engagement with the abutment or the bushing; the platemay be shifted while the. floating punch is at full libertyvto dance through the bushing while the new punching location is being arrived at. distance as is vpermitted by the bushing, and this distance should not be so great asito interfere with the steering of a new plate: under the pu-ncho The punch may descendysuch limited If the plate be withdrawn then the above mentioned program would hold good- With a plate of'the illustrated thickness. But if a plateof, say, half the thickness ofnthe illustrated one were-inserted, then the punch I could notfloat down to it, being held up'too high by the bushing. An, ustment must be made to takecare of the new distance between the upper surface: of the plate; and

the ram, and this may be taken care of by raising the die, asby means of such a shim as 17, illustrated in Fig. 5, or it may be taken care of by -lowering the bushing, whichris to be done by loosening block 15 and unscrewing the bushing downwardly the proper distance. Within certain limits it is obvious that no adjustment either of the punch or the die will be necessary, the point being that thepunch will be capable of floating on the plate without being sustained away therefrom by the ram. And it is also obvious that in case continuous work is being done upon plates of unvarying thickness no provision whatever need be made for adjusting either the die or the punch.

Many punching machines are used also for shearing, and the loss of motion at the top of the stroke which is here employed in connection with a floating punch, may be undesirable when the machine is employed for shearing. This matter is readily taken care of by simply shifting the switch-ring to such position that the ram will come to rest at its topmost limit-of stroke.

1. In a floating punch, the combination, of a die, a ram reciprocable to and from the die, a stripper disposed between the die and ram, a downwardly presenting abutment carried by the ram, an upwardly presenting abutment carried by the ram, a punch reciprocable in the ram, an upwardly presenting surface connected with the punch and adapted for contact with the downwardly presenting abutment of the ram, a downwardly presenting surface connected with the punch and adapted'for contact with the upwardly presenting abutment of the ram and located at a distance from said upwardly presenting surface in excess of the distance between the two abutments ofthe ram whereby thepunch may have a limited degree of reciprocation in the ram when the ram is at an intermediate point of its stroke, and means for arrest- Gopies of this patent may be obtained for five cents each, by addressing the ing the motion of the ram when both its abutments are free of contact with the punch and said surfaces of the punch are free to reciprocate between said abutments, substantially as set forth..

2. A structure as specified in claim 1 in combination with means for adjusting the distance between the die and the punch when the punch is supported by the ram in stationary condition, substantially as set forth.

3. A structure as specified in claim 1 in combination with means for adjusting the protrusion of the punch from the ram when no plate is present for the punch to float upon, substantially as set forth.

4. A structure as specified in claim 1 in combination with a cam-shaft and clutch for efiecting the arrest of the ram while the punch is floating on the plate, substantially as set forth.

5. A structure as specified in claim 4 in combination with an automatic clutch for efiecting the automatic arrest of the ram while the punch is floating on the plate, substantially as set forth.

6. A structure as specified in claim 1 in combination with a bushing adjustably screwed into the base of the ram to form the lost motion connection between the punch and the ram, substantially as set forth.

7 A structure as specified in claim 6 in combination with means for locking the bushing against rotation, and a radial screw carried by the bushing and engaging a keyway in the punch, substantially as set forth.

8. A structure as specified in claim 6 in combination with a block clamped to the base of the ram and forming part of the threaded socket for the reception of the bushing and forming in addition a locknut for the bushing, substantially as set forth.

PAUL G. PATER.

WVitnesses CHARLES VOLLBREGHT, M. S. BELDEN.

Commissioner of Patents,

Washington, D. G. 

